1. Technical Field
The present invention relates to the field of machines for cartoning products.
2. Description of the Related Art
The cartoning of products inside cardboard boxes substantially involves the following operations: forming boxes from cardboard blanks; receiving incoming products from one or more infeeds; loading products into the boxes according to a given grouping, closing of the boxes.
According to prior art, the packaging lines dedicated to performing these operations comprise: a box forming section; at least one loading robot; a closing section; and at least one linear translation system.
In the forming section, a device such as a male part cooperating with a die forms the cardboard boxes from flat blanks. The boxes are transferred from the forming section to said linear translation system, and are then loaded by said at least one robot.
More specifically, in intermittent lines or intermittent machines the translation system stops at a loading station, so that the box remains open and stationary during the loading phase, which comprises one or more work cycles of the above-mentioned robot. Said robot may for example be a two-axis robot equipped with a suitable pick-up device. In other lines or machines, loading may be performed by 4-axis robots capable of line-tracking the boxes; in this case the load is termed “in tracking”. The loading follows a pre-determined grouping, corresponding to a certain number of units of products per box. The closing section operates by applying glue or by other equivalent means.
According to the prior art, the packaging lines that perform these operations are formed by several machines connected by conveyor belts. For example, a line comprises a carton forming machine, a robotized loading station and a closing machine that are separate from each other. The boxes are transferred from the loading station to the closing machine by an auxiliary conveyor belt which acts as the connection interface between the loading station and the closing machine.
This approach is known however to limit the maximum speed of the machine. In fact, the closing machine must maintain the same production speed of the sections upstream, that is to say that the closing machine must process the same number of boxes per minute that are respectively formed and loaded; to this purpose, it has been noted that the transfer of boxes from the loading station to a closing machine by an auxiliary conveyor belt is unable to reach and reliably maintain the high operating speeds that are more and more frequently required by the market. In other embodiments, robots are used to transfer the boxes to the closing devices and/or to perform the closing operations. The use of robots for operations such as closing the boxes, which are considered secondary operations compared to loading, involves an increase in costs particularly if the robot must operate at high speeds.